The present invention relates to a position control system for a radial drilling machine. The proposed system renders the increase of accuracy, the automation of positioning possible.
The object of the invention is to provide a method for position controlling a drill spindle with respect to bore centers which are determined in a rectangular coordinate system in which the workpiece can be arranged in any position on a base plate.
The difficulties of processing carried out by a radial drilling machine reside in that the drill spindle can be actuated along a circle and a straight line over different workpieces arranged on the base plate. Therefore the position of the drill spindle would be best if determined in polar coordinates. The workpieces, however, are mostly represented on factory drawings in rectangular coordinates showing the orientation of the workpiece and the bores to be prepared in it. Under factory conditions it is difficult to measure the angles with high accuracy and, especially in case of workpieces with sophisticated surface relief, the use of angles on a drawing would result in difficulties. Therefore the known position methods and controls cannot be used.
In case of radial drilling machines two methods have been followed for positioning during preparing the workpieces and the machine boring. The first of them preferred for long series production and includes the application of a bored mask plate. This is placed on the workpiece and the holes in the mask are used for orientation of the drilling spindle. For preparing individual workpieces the second method is preferred according to which guiding marking holes are made in the places where boring should be performed.
The first method is characterized with low accuracy. The second requires a high amount of work.
U.S. Pat. No. 4,043,700 discloses a device for positioning the spindle of a radial drilling machine wherein the spindle is movable in a rectangular coordinate system determined by an appropriate arrangement of frames. The system is clearly mechanical, relatively sophisticated and the frames place limitations on its use.